The sense of taste is important both for food selection and digestion. The gustatory system can be divided into two functionally and anatomically distinct channels, a facial nerve channel and a vagal nerve channel. These two gustatory channels each maintain distinct sensory regions in the medulla and higher levels of the neuraxis. A comparison will be made of the central nervous system structures involved in each of these gustatory channels. Connections of the gustatory nuclei will be examined by means of autoradiographic, degeneration and enzyme (horseradish peroxidase) tracing techniques. Differences and similarities in neurotransmitters and neuropeptides involved in the gustatory nuclei will be sought by means of immunocytochemical and histochemical methods. The morphology and synaptic interrelationships of the various gustatory nuclei will be examined at the light and electron-microscopic levels. The possibility of growth in the vagal lobe will be examined by tritiated thymidine techniques.